肥胖兒童相較於正常者其心跳較高,HRV較低,運動訓練後心跳及HRV改善較大

Heart Rate Variability in Obese Children: Relations to Total Body and Visceral Adiposity, and Changes with Physical Training and Detraining


Obesity Research (2000) 8, 12–19; doi: 10.1038/oby.2000.3

http://www.nature.com/oby/journal/v8/n1/full/oby20003a.html#tbl2





Bernard Gutin*, Paule Barbeau*, Mark S. Litaker†, Michael Ferguson* and Scott Owens*

1. *Georgia Prevention Institute, Department of Pediatrics, Medical College of Georgia, Augusta, GA 30912 and the

2. †Office of Biostatistics, Medical College of Georgia, Augusta, GA 30912

Correspondence: Bernard Gutin, PhD, HS1640 Medical College of Georgia, Augusta, GA 30912. E-mail: bgutin@mail.mcg.edu

Received 17 March 1999; Accepted 6 May 1999.



Abstract
Objective: Heart rate variability provides non-invasive information about cardiac parasympathetic activity (PSA). We determined in obese children: (1) relations of baseline PSA to body composition and hemodynamics; (2) effects of physical training (PT) and cessation of PT; and (3) which factors explained individual differences in responsivity of PSA to the PT.

Research Methods and Procedures: The root mean square of successive differences (RMSSD) was the index of PSA. Obese children (n = 79) were randomly assigned to groups that participated in PT during the first or second 4-month periods of the study.

Results: Baseline RMSSD was significantly (p < 0.05) associated with lower levels of: fat mass, fat-free mass, subcutaneous abdominal adipose tissue, resting heart rate (HR), resting systolic blood pressure, and exercise HR. Stepwise multiple regression produced a final model (R2 = 0.36) that included only resting HR. The analysis of changes over the three time points of the study found a significant (p = 0.026) time by group interaction, such that RMSSD increased during periods of PT and decreased following cessation of PT. Greater individual increases in response to the PT (p < 0.05) were seen in those who had lower pre-PT RMSSD levels, showed the greatest decreases in resting HR, and increased most in vigorous physical activity. The final regression model retained only the change in resting HR as a significant predictor of the changes in the RMSSD (R2 = 0.23).

Discussion: Regular exercise that improved fitness and body composition had a favorable effect on PSA in obese children.

Keywords:
parasympathetic activity, exercise, body composition